sì yī èr
12th April
refers to Chiang Kai-shek's coup of 12th April 1927 against the communists in Shanghai
sì yī èr fǎn gé mìng zhèng biàn
counterrevolutionary coup of 12th April 1927, Chiang Kai-shek's coup against the communists in Shanghai
sì yī èr shì biàn
the coup of 12th Mar 1927, an attempt by Chiang Kai-shek to suppress the communists
called 反革命政变|反革命政變 or 慘案|惨案 in PRC literature
sì yī èr cǎn àn
the massacre of 12th Mar 1927
the Shanghai coup of 12th Mar 1927 by Chiang Kai-shek against the communists